Statins are a class of pharmaceuticals that inhibit the enzyme hydroxymethylglutaryl CoA reductase (HMG-CoA-R) and are therefore widely used as hypolipidaemic agents and agents that lower the level of cholesterol in the blood (hypocholesterollipidaemic agents). All synthetically prepared HMG-CoA-R inhibitors have, as common structural features, an aromatic base structure and the so-called statin side chain, as symbolised by the following formula:

(wherein Aryl denotes aromatic, heterocyclic or aromatic-heterocyclic, unsubstituted or substituted, mono-, di- or poly-cyclic ring systems). Such a structural unit can be found in a whole range of pharmaceutically active agents, such as cerivastatin (Bayer AG), fluvastatin (Novartis), itavastatin (NK-104; Kowa Company Ltd.), BMY 22089 (Bristol-Myers Squibb), rosuvastatin (S-4522, AstraZeneca/Shionogi), glenvastin (Hoechst(Aventis) and atorvastatin (Warner-Lambert/Gödecke-Parke Davies/Pfizer).
The aim of the present invention is to provide new efficient methods of synthesising some known statin derivatives and to provide new intermediate compounds.